Auxiliary automatic heat exchange system for internal combustion engines



Feb. 22, 1966 J O. HQLMES 3,236,220

AUXILIARY AUTOMATIC HEAT EXCHANGE SYSTEM FOR INTERNAL COMBUSTION ENGINESFiled June 29, 1964 2 Sheets-Sheet l N INVENTOR.

JOHN Q. H04 M55 BY C/ma THEKSAuo (hear/mu /-//.s A v-raeus v.5

Feb. 22, 1966 J O. HOLMES 3,236,220

AUXILIARY AUTOMATIC HEAT EXCHANGE SYSTEM FOR INTERNAL COMBUSTION ENGINESFiled June 29, 1964 2 Sheets-Sheet 2 llllll n-m I N VENTOR. JOHN6114044465 CAEO THERS AND (nee THEES HA: 4 r TOEA/E Y5 United StatesPatent T 3,236,220 AUXILIARY AUTOMATIC HEAT EXCHANGE SYSTEM FOR INTERNALCOMBUSTION ENGINES John Q. Holmes, 1596 Timber Road, Mansfield, OhioFiled June 29, 1964, Ser. No. 378,897 8 Claims. (Cl. 1Z3-142.5)

This invention relates generally to a heat exchange system to aid thestarting of internal combustion engines and more particularly to a fullyautomatic control for a heat exchange system to be used in startinginternal combustion engines.

The prior art in the field of heat exchange systems for assisting in thestarting operation of internal combustion engines is voluminous.Structures are shown in the art that mechanically, through means such asgas or electric power, heat the liquid coolant in the cooling system ofthe engine and circulate it back into the Water jacket of the engine.Circulation of the coolant may be accomplished purely by thethermosiphonic theory or by the more eflicient method of using a pump.The piror art has illustrated automatic control for the operation ofthese heat exchange systems but such controls are not a completeautomatic system with necessary safeguards. Furthermore, previousautomatic control systems have developed into complex control systemswhich limit their practicability which need is more frequent than not.

The principal object of this invention is the provision of anindependent heat exchange system for any liquid cooled internalcombustion engine with fully automatic temperature and circulatoryoperation and control.

Another object of this invention is the provision of a heat exchangesystem to aid in the starting of internal combustion engines.

Another object of this invention is the provision of a heat exchangesystem to minimize the risk of damage to the engine or coolant systemdue tothe solidification of the coolant in colder temperatures. Inconnection with this point, the automatic control of this inventionwould eliminate need of freezing preventative in the coolant which wouldnot only eliminate the expense but also the corrosive action on thecoolant system caused by many of these preventatives.

Antoher object of this invention is the provision of less complex heatexchange system for starting internal combustion engines yet is fullyautomatic needing no human or outside system after once initially setand is portable and capable of use on machinery which, during nonuse, iseither housed within a building or is left outside or at the place wherethe machinery is being employed.

Other objects and advantages appear hereinafter in the followingdescriptions and claims.

The accompanying drawings show for the purpose of exemplificationwithout limiting the invention or claims thereto, certain practicalembodiments illustrating the principles of this invention wherein:

FIG. 1 shows a schematic view of heat exchange system and automaticcontrol for the same comprising this invention.

FIG. 2 is a side elevation of the heat exchange system showingarrangement of the components thereof.

FIG. 3 is a perspective view showing the application of a portablearrangement of the heat exchange system of this invention to acrawler-type tractor.

Referring to FIG. 1, the illustration therein made is to demonstrate ina simple form the features comprising this invention. This has beenillustrated exclusive of any attempt to show a practical and logicalarrangement of the mechanical and electrical components of the systemand control. FIGS. 2 .and 3 clearly illustrate the practical and3,236,220 Patented Feb. 22, 1966 logical application of the inventionand component arrangement.

Engine 1 represents an internal combustion engine having a coolantsystem including radiator 2. The heat exchange tank 3 may be connectedto the inlet 4 and outlet 5 of the engine coolant jacket of theengine 1. The coolant flows through the couplings 6. The male portion 7of the coupling 6 is illustrated in FIG. 2. It should be noted as apractical matter the couplings 6 in the circulatory system of FIG. 1would not be used as such but would be located on the engine block 1.Thus, the female valve portions (not shown) of the coupling 6 would beon the engine block 1 and the valve would open upon coupling with themale portion 7. The male portion 7 would be on the tank 3. The heatexchange tank 3 may be connected directly to the engine 1 or connectedthrough the hose members 8 and 10. The use of so-called quick couplersprovide easy maintenance of a fleet of internal combustion engines. Thevalve type couplings may also be provided on the tank 3 so as to retainany coolant in the tank upon disconnection of the tank from engine 1.

The pump 11, usually the centrifugal type, will pump the coolant fromthe engine coolant jacket at outlet 5 through supply line 10 to thelower portion of the heat exchange tank 3.

A thermostat-solenoid control 12 is provided in line 10. Line 10 mayalso the provided with a solenoid valve 13 and a check valve 14.

Return line 8 returns the heated coolant to the engine block 1 at inlet4. A thermolimit switch 15 may be provided in line 8 as a safety featureto .be explained below. Thus, a complete enclosed, but independent,coolant circulatory system is provided between the engine 1 and the heatexchange tank 3.

It should be noted that check valve 14 and pump 11 permit flow only inone direction and thus the fluid coolant circulated is permitted only toenter at 4 and exit at 5 of the engine 1. This flow will be opposite tothe coolant flow when the engine 1 is in actual operation, in the caseof most internal combustion engines. However, coolant flow may bereversed from that shown in FIG. 1 by interchanging the couplingconnections 6 and the same results will be obtained as far astransferring heat to and exchanging heat within the engine block 1. Theadvantage of the arrangement as shown in FIG. 1 resides in the fact thatsuflicient coolant is readily obtainable from the radiator 2 as Well asthe engine block 1. However, the disadvantage resides in a much longerperiod of time to heat the coolant and subsequently the engine block.With the connections reversed only the coolant in the engine block 1will circulate, thus providing the most rapid method of heating theengine block 1.

The heat exchange tank 3 may be of any construction well known in theart. A simple construction is that shown in the drawings wherein aninner cylindrical wall 16 is placed within an outer cylindrical wall 17.The

space between the walls 16 and 17 is sealed at both ends thereof. T-heseends form a bottom 18 and top 20. The interior of the cylinder 16 isopen at both ends and a diffuser 21, such as shown in FIG. 2, may beplaced upon the upper end of the cylinder 16. Thus, the two cylindricalwalls 16 and 17 together with the bottom 18 and top 20 form acylindrical enclosure 22 for the coolant which enters the tank 3 at theinlet 23 near the bottom 18 and departs at the outlet 24 near the top20. The coolant may circulate throughout the chamber or enclosure 22 andreceive heat energy from the wall 16 and finally flow from the outlet 24back to the engine 1 for circulation.

A burner 25 is provided at the bottom 18 of the tank 3 which providesthe necessary heat to the cylinder 16 and tank 3 in order that thecoolant fluid will be heated 3 a sufiicient degree during its upwardcirculation in the chamber 22.

The burner 25 may be supplied with any convenient combustible gas suchas propane. Bottled gas 26 is provided for storage of the gas in orderto give the heat exchange system as much portability as possible. Thesupply line 27 to the burner 25 may be provided with an electric gasvalve 28 as a safety precaution and also prevent any passage of gas tothe burner 25 when the heat exchange system and control is not inoperation. A valve 30 may also be provided in supply line 27 in order toadjust the flow of gas to the burner 25.

FIG. 1 shows the electrical circuit for the control of the heat exchangesystem. The electrical power to the circuit may be provided either bybattery 31 or from any convenient electrical A.C. outlet or A.C. powersource 32. In order to provide the necessary direct current for thecircuit control, a D.C. converter may be employed between the circuitand A.C. source. Such converters are well known in the art and consistof a tap transformer 33 wherein a reduced voltage is taken from thesecondary 34 of the transformer and Supplied to the full wave rectifier35. A direct current is taken from the output 3637. The current may bemade of constant or smooth generation by supplying the capacitor 38 ofpredetermined value at the output.

By arranging the circuit to operate from a low voltage source such as 12volts, the system may be operated from the battery supply of the vehicleor machinery itself. This battery supply is represented by 31. On theother hand, switch 40 may be opened and the power may be supplied to thecircuit from the DC. converter upon closing of switch 41.

From either switch 40 or 41, the power is supplied through line 42 tothe timer 43 marked T. Thus, the circuit will not operate unless thetimer is set to permit passage of the current. The timer 43 is set for apredetermined time so that the heat exchange system will only begin tooperate when necessary.

From the timer 43, line 44 is connected to line 45 through the contact46 of the thermolimit switch 15. Switch 15 is in the return line 8 ofthe heat exchange system and operates to open its contact when thecoolant flowing through return line 8 reaches a high predeterminedtemperature. Thus, for a water type coolant system, the return supply ofcoolant should not exceed the boiling point of water. The thermoswitch15 is set to operate at 200 F. and its normally closed contact 46 willremain closed until the temperature of 200 F. is reached whereupon theswitch will operate, opening its contact 46. The temperature is notexpected to reach such a high value, but if the thermostat 12 is notoperatmg properly within its set limits, the thermolimit switch 15 willact as a safety precautionary feature and prevent the coolant from beingcirculated at an unnecessary high temperature which may be detrimentalto the engine as well as the heat exchange system. The thermolimitswitch 15 is provided with a manual reset.

Line 45 is connected to the contact 47 of the thermostat or thermoswitch12 which in turn is connected by line 48 to the solenoid valve 13. Thethermostat 12 is set within a predetermined temperature range. Thus, inthe case of diesel engines, for efiicient starting the engine temperature should be above the freezing point. A thermostat set within therange of 49 F. to 62 F. will cause the contact 47 to open if the coolantfrom the engine 1 has reached at least 62 F. If either the coolant fluidtemperature in supply line or the atmospheric temperature is below 49F., the contact '47 will be made to close so that the control circuit ofthe heat exchange system will go into operation. Thus, thermostat 12 isthe very heart of the control circuit operating, if the timer 43 is setto operate also, to heat the coolant fluid in the engine 1 if itstemperature has dropped below a predetermined value.

Thefluid solenoid valve '13 is not'an essential component of the systembut will not permit passage of fluid coolant to the tank 3 unless thethermostat 12 is in operation closing its contact 47. Solenoid valve 13though not essential is important to prevent any back pressure fromforcing the coolant in the lines back through the pump 11 after thesystem is shut off. Any possibility of seal rupture in the pump iseliminated.

Connected across the supply source through line 50 is the motor 51 whichoperates the pump 11. Also connected across the supply source is thecoil 52 which supplies periodically stored potential to the distributor53 which in turn distributes this at intervals to the spark plug 54. Theelectric gas valve 28 is also connected across the supply source. Themotor 51 and electric gas valve 28 are connected through return line 55to the negative side of the power source which is grounded. Thedistributor-coil combination is of the type commonly found on ignitionsystems of vehicles and is only shown here as a means to supply thenecessary ignition to the gas escaping from the burner 25. A highvoltage is obtained from the coil 52 which, through a cam 56, contactpoints and rotor 57 of the distributor 53, is distributed frequently tothe air gap 58 of the spark plug 54. This developed high A. C. frequencyproduces a succession of sparks at the air gap 58 which will ignite thegas from the burner 25. The spark ignition system used in electricfurnace control is also available to supply an ignition system for theheat exchanger of this invention.

Another type of ignition system to ignite the gas escaping from theburner 25 is the piezoelectric ignition system which utilizes theprinciple of producing an electrical charge due to change of stresswithin the crystalline material. The crystalline materials capable ofproducing the piezoelectric eifect are ceramic materials such aslead-zirconate-titanite ceramics. Thus by applying a force to such aceramic material, causing the material to be placed under stress due tocompression by an outside force, a spark gap connected to the two endsof the same ceramic will produce a spark upon such compression. Thistype of generator or commonly called spark pump may be operated from theshaft of the electric motor 51 which operates the pump 11. The shaft mayemploy a cam means which upon rotation by the electric motor 51 wouldcome in contact with the actuating lever of the spark pump. Theactuating lever would in turn compress the ceramic element, causing aspark at the air gap 58. If the force created by the motor 51 on theactuating lever of the spark pump is not of sufficient magnitude, aforce multiplication system may be incorporated in the spark pump, whichsystem is now known in this particular art.

A thermocouple 60 may be provided with its contact end in the flame ofthe burner 25. The heat energy will cause a small electron flow orcurrent in the lines 61 and 62 which will energize the low voltagesensitive relay 63 causing it to open its contact 64 which is in line50. Thus, after the flame appears at burner 25 upon ignition by the plug54, the relay 63 will discontinue the supply of current to the coil 52and eliminate continued sparking at the air gap 58. Such a control isnot necessary but reduces the power necessary to be supplied to thecontrol circuit after once in operation. On the other hand, thethermocouple-relay combination is a constant spark ignition. It istherefore a safety feature in that if the gas flame would everextinguish during operation of the heat exchanger, the thermocouple 60would permit the relay 63 to close its contact 64 upon sufficientcooling of the former, thus permitting the ignition system to againignite the gas escaping from the burner 25.

FIG. 2 shows suggestively, the arrangement of circuit components on theheat exchange tank 3 thus giving the complete assembled systemacceptable portability. The gas supply 26 may be removably secured tothe tank 3 as indicated at 65.

The thermostatic control 12 may be placed on either side of the pump 11and check valve 14. In FIG. 1, the thermostat control 12 is before thepump 11. In FIG. 2, the thermostatic control is placed in supply linebetween the check valve 14 and the heat exchange tank 3. In the formerposition, the control 12 will be sensitive to coolant fluid temperaturechange as well as atmospheric temperature change. In the latterexplained position shown in FIG. 2, the control 12 will be onlysensitive to atmospheric temperature change since the solenoid valve 13will not permit fluid passage until the circuit is activated by thetimer 43 and the control 12 itself.

FIG. 3 illustrates that upon reduction of the size and capacity of theheat exchange tank 3 and necessary gas supply tank 26, the unitcomprising this invention along with the electrical control placedwithin a box 66 with fluid lines S and 10 intercepting circuit elementsas shown in FIG. 1 may be secured to the side of the tractor 67 by anyconvenient clamping method. Thus, the unit may remain with the vehicleupon which it is to operate for an indefinite period of time. Theoperator, after the daily work is completed, need only set the timer 43upon leaving the tractor 67. The power supply 31 may be the battery ofthe tractor 67. If upon actuation of the circuit by the timer 43, thethermostat 12 has closed its contact 47 due to an atmospherictemperature below the prede termined setting, the heat exchange systemwill begin to operate by opening the solenoid valves 13 and 28 and byoperation of the pump 11 and coil-distributor system through motor 51.As the coolant is circulated from engine 1 to heat exchange tank 3 andback, the coolant fluid will be heated sending warmth to all parts ofthe engine block 1 heating toe block to a sufiticient degree renderingthe starting operation easier. This is especially true in the case ofdiesel engines which will not start easily in sub-freezing weather dueto the character of their combustible operation. When the coolant fluidreturning to the heat exchange tank reaches the higher of the twopredetermined temperature settings in the thermostat 12, the contact 47is opened and the operation of the system is extinguished until theatmospheric temperature reduces the coolant fluid to a temperature belowthe lower of the two predetermined temperature settings in thethermostat 12, whereupon the cycle of operation begins operation again.

An example of operation is as follows: During the colder months of theyear where diesel vehicles must be left outside without protection fromatmospheric conditions present during that time of year, the timer 43may be set for operation at 5:00 am. where the operator must operate thevehicle the next morning at about 5:30 am. The atmospheric temperatureis 8 F. during the night. Thus, at 5:00 a.m. the timer 43 actuatespermitting current supply to the circuit. The thermostat 12 is setwithin an operation range of 49 F. to 62 F. Since the temperature isbelow 49 F., the contact 47 is closed and, as explained above,circulation is started by pump 11. The solenoid valves 13 and 28 areopened and the ignition system ignites the burner 25. As soon as thecirculating liquid reaches 62 F., the thermocontact points in thermostat12 open the contact 47. Since the circuit is open, the heat exchangesystem will not operate until the temperature of the thermostat 12 isbrought back down to at least 49 F. through the natural heat exchange ofthe coolant and engine block with the atmosphere. In the meantime, thediesel engine 1 is sufliciently warmed up to commence immediateoperation by the operator at 5:30 am.

As a safety feature, if the coolant fluid returning to the engine block1 in line 8 should in some way become heated to a greater degree thannecessary through a malfunction in the circuit, such as the sticking ofthe thermostat 12 or stalling of the motor 51, thermoswitch 15 will openits contact 46 and thus completely shut ofif the heat exchanger andcontrol until the switch 15 is manually reset. The heat exchange systemis protected from damage due to overheating.

I claim:

I. In a heat exchange system for heating the coolant fluid in thecooling system of an internal combustion engine comprising a heatexchange tank means having an inlet and an outlet, a supply line fromsaid engine cooling system to the inlet of said tank means, a returnline from the outlet of said tank means to said engine cooling system, acombustible gas burner at the bottom of said tank means and having acombustible gas supply, pump means in said supply line to circulate thecoolant fluid of said cooling system through said lines and said tankmeans, an electrical control circuit to operate said heat exchangesystem having a power source, said electrical control circuit includinga thermostatic control in said supply line having a front contactconnected in series in said circuit and normally open between a maximumtemperature limit and a minimum temperature limit when the coolant fluidtemperature is first raised to said minimum temperature limit, asolenoid operated valve connected between said gas supply and saidburner and electrically connected across said power source to open thevalve upon energizing the solenoid to permit passage of combustible gasto said burner, a mot-or means connected across said power source tooperate said pump means in said supply line, and an electrical ingnitionsystem connected across said power source to ignite the combustible gasescaping from said burner.

2. The heat exchange system of claim 1 characterized by a timerconnected in series in said electrical control circuit to permitoperation of said heat-exchange system at a predetermined time.

3. The heat exchange system or claim 1 characterized by a solenoidoperated valve connected in at least one of said lines and electricallyconnected in series in said control circuit to permit passage of thecoolant to or from said engine cooling system and said tank means whensaid electrical control circuit is in operation.

4. The heat exchange system of claim 1 characterized by a thermolimitswitch in said return line and having a front contact connected inseries in said circuit to open when the coolant fluid reaches a highpredetermined temperature.

5. The heat exchange system of claim 1 characterized in that saidelectrical ignition system comprises a high frequency generator toproduce a high voltage, a distributor means connected to said generator,a spark gap positioned at said gas burner and electrically connected tosaid generator and said distributor means to cause a spark within saidgap to ignite the combustible gas escaping from said burner.

6. The heat exchange system of claim 5 characterized in that saiddistributor means is operated by said motor means.

7. The heat exchange system of claim 1 characterized by a low voltagerelay having a front contact connected in series with said electricalignition system, thermocouple means positioned to be within the flamecaused by ignition of the combustible gas escaping from said burner,said thermocouple means electrically connected across said relay, saidfront contact of said relay to open upon energizati-on of said relaycaused by an electrical current generated from heat on saidthermocouple.

8. The heat exchange system of claim 1 characterized in that saidthermostatic control in said supply line having a front contactconnected in series in said circuit is normally open between a maximumtemperature limit and a minimum temperature limit when the coolant fluidtemperature is first raised to said maximum temperature limit.

No references cited.

KARL J. ALBRECHT, Primary Examiner.

1. IN A HEAT EXCHANGE SYSTEM FOR HEATING THE COOLANT FLUID IN THECOOLING SYSTEM OF AN EXTERNAL COMBUSTION ENGINE COMPRISING A HEATEXCHANGE TANK MEANS HAVING AN INLET AND OUTLET, A SUPPLY LINE FROM SAIDENGINE COOLING SYSTEM TO THE INLET OF SAID TANK MEANS, A RETURN LINEFROM THE OUTLET OF SAID TANK MEANS TO SAID ENGINE COOLING SYSTEM, ACOMBUSTIBLE GAS BURNER AT THE BOTTOM OF SAID TANK MEANS AND HAVING ACOMBUSTIBLE GAS SUPPLY, PUMP MEANS IN SAID SUPPLY LINE TO CIRCULATE THECOOLANT FLUID OF SAID COOLING SYSTEM THROUGH SAID LINES AND SAID TANKMEANS, AN ELECTRICAL CONTROL CIRCUIT TO OPERATE SAID HEAT EXCHANGESYSTEM HAVING A POWER SOURCE, SAID ELECTRICAL CONTROL CIRCUIT INCLUDINGA THERMOSTATIC CONTROL IN SAID SUPPLY LINE HAVING A FRONT CONTACTCONNECTED IN